New drive to stop killer malaria

By Peter Orengo

Scientists have announced a new initiative towards a vaccine that may effectively block transmission of malaria from mosquitoes.

The Path Malaria Vaccine Initiative (MVI) in collaboration with the Johns Hopkins Bloomberg School of Public Health (JHSPH) and the Sabin Vaccine Institute (Sabin) have invested in transmission-blocking vaccines (TBVs) that will stop the malaria parasite from developing in the mosquito.

Over the next 18 months, the partners will collaborate to produce and characterise an antigen that can activate the body’s defences to disrupt human-mosquito transmission cycle of malaria.

An antigen is any substance that triggers the immune system to produce antibodies against it.

The development team will identify optimal conditions needed to manufacture clinical supplies of AnAPN1, a mosquito antigen that appears to play a major role in parasite establishment within the mosquito.

Preliminary field research has shown antibodies induced by this antigen are capable of blocking transmission of the two deadliest malaria parasites, Plasmodium falciparum and Plasmodium vivax.

When a mosquito takes blood from a vaccinated person, these antibodies prevent the parasite from attaching to and invading the mosquito’s gut.

Tremendous impact

"The antibodies that we have produced are effective against multiple malaria parasites and, therefore, this antigen may constitute the basis for a future ‘universal’ or pan-malaria transmission-blocking vaccine," said Dr Rhoel Dinglasan, lead researcher of the project and faculty member at JHSPH.

He added: "This could have a tremendous impact on malaria transmission, even extending beyond those individuals we can reach through a vaccination campaign."

Malaria kills nearly 900,000 people yearly, most of them children below five years.

"The heart-breaking devastation caused by malaria cannot be overstated. Blocking transmission by novel vaccines may provide the approach needed to stop the epidemic," said Dr Peter Agre, Nobel Laureate and Director of the Johns Hopkins Malaria Research Institute.

This collaboration is MVI’s first project focused on TBVs.